双通道原子荧光光谱法同时测定土壤中的砷和汞

对现有国标检测方法(GB/T 22105.1-2008和GB/T 22105.2-2008)进行改进,采用王水水浴浸提-双通道原子荧光光谱法同时测定土壤样品中砷、汞的含量。采用土壤国家一级标准物质GSS-3,GSS-8,GSS-9与山西农田土壤样品为试验对象,筛选得到检测砷、汞元素含量最佳实验条件及仪器工作条件。砷、汞的质量浓度分别在0~150μg/L,0~2μg/L范围内与荧光强度成良好的线性关系,线性相关系数均大于0.999,砷、汞的检出限分别为0.021,0.0015 mg/kg。测定结果的相对标准偏差为1.81%~4.64%(n=8),砷、汞的样品加标回收率分别为92.7%~103.0%,82.0%~95.5%。经国家一级标准物质验证,该法检出限、准确度和精密度均满足检测要求。改良后的方法可以同时准确、快速地测定土壤中砷、汞,极大地提高了工作效率,可以更好地适应当前大量的土壤分析工作。

Determination of arsenic and mercury synchronously in soils with dual-channel atomic fluorescence spectrometry

The testing methods(GB/T22105.1-2008 and GB/T22105.2-2008)were improved,the arsenic and mercury in soil samples were determined simultaneously by aqua regia water bath extraction-dual channel atomic fluorescence spectrometry.The optimal experimental conditions and working conditions of instrument for the detection of arsenic and mercury were selected by national first-class standard reference materials of GSS-3,GSS-8,GSS-9 and farmland soil samples of Shanxi.The mass concentration of As and Hg had good liner relationship with the fluorescence intensity in the range of As 0-150μg/L,Hg 0-2μg/L.The correlation coefficients were all more than 0.999.The detection limits of As and Hg were 0.021,0.0015 mg/kg,respectively.The relative standard deviations of determination results were 1.81%-4.64%(n=8).The recoveries were 92.7%-103.0%for As and 82.0%-95.5%for Hg,respectively.The method was applied to the determination of As and Hg in national first-class standard reference materials,the detection limit,accuracy and precision of this method were in agreement with the certified values in national first-class standard reference materials.The improved method can accurately and quickly determine As and Hg in soil simultaneously,which greatly improves the work efficiency,so it can better adapt to the current large number of soil analysis work.